1. Field of the Invention
This invention relates to colored pigment compositions of high refractive index and hue intensity and aims generally to improve the same and provide novel processes for the production thereof.
2. Description of the Prior Art
In the prior art it has been well known to produce the so-called "laked" or "extended" pigment colors usually by precipitation of a soluble organic dye or pigment color base onto an inert and inherently colorless or white substrate material to impart either useful pigmentary properties to an otherwise unsuitable organic or inorganic color material or to give improved physical properties to an already useful color. Such treatments and combinations included the enclosing or encapsulation of inorganic color material, such as the lead chromate yellows with a siliceous envelope or encapsulation, to inhibit or reduce its toxicological properties, and also included the laking of azo and releated organic pigments on such insoluble substances as alumina, blanc fixe and similar compositions.
The said methods simply dilute the color portion of the final pigment composition and essentially result in a wet or dry dispersion of the color pigment or chromogen containing part intimately admixed with the inert or extender portion of the composition.
Such laked or extended colors are usually considerably duller than the original chromogen containing constituent and not infrequently are themselves easily disunited into the separate components of the composition. This is especially true concerning the use of mixtures of organic color pigments per se with the so-termed substrate or extender inorganic pigment compounds.